EP 0671632 B1 20011212 - Field winding ground fault detector and relay
Title (en)
Field winding ground fault detector and relay
Title (de)
Erdschlussdetektor und Schutzrelais für Erregerwicklungen
Title (fr)
Détecteur de court-circuit à la masse et relais de protection pour un enroulement d'excitation
Publication
Application
Priority
JP 2858094 A 19940225
Abstract (en)
[origin: EP0671632A2] According to a field ground fault detector, a predetermined resistor is connected in series to a predetermined DC voltage. A DC voltage is applied between an N electrode side field circuit of a generator and a ground through the resistor. A voltage applied between terminals of the resistor is input to a low-pass filter. A voltage applied between the N electrode side field circuit and the ground is input to another low-pass filter. Output voltages of the low-pass filters are input to a level ratio determining circuit. The level ratio determining circuit outputs the determined result of the ground fault to the outside of the field ground fault detector corresponding to these voltages. Thus, even if the DC voltage varies or a higher harmonic voltage takes place in a generator of a thyristor exciting type, it does not affect the detecting sensitivity of the ground fault. <IMAGE>
IPC 1-7
IPC 8 full level
G01R 31/06 (2006.01); H02H 3/17 (2006.01); H02H 7/06 (2006.01); H02P 9/30 (2006.01)
CPC (source: EP KR US)
G01R 31/346 (2013.01 - EP US); H02H 3/00 (2013.01 - KR); H02H 7/065 (2013.01 - EP US); G01R 31/52 (2020.01 - EP US)
Designated contracting state (EPC)
CH DE FR GB LI SE
DOCDB simple family (publication)
EP 0671632 A2 19950913; EP 0671632 A3 19960918; EP 0671632 B1 20011212; CA 2143364 A1 19950826; CA 2143364 C 20011127; CN 1045821 C 19991020; CN 1112682 A 19951129; DE 69524463 D1 20020124; DE 69524463 T2 20020718; JP 3468817 B2 20031117; JP H07241027 A 19950912; KR 100206027 B1 19990701; KR 950026073 A 19950918; US 5675465 A 19971007; US 5764462 A 19980609
DOCDB simple family (application)
EP 95301146 A 19950222; CA 2143364 A 19950224; CN 95100865 A 19950225; DE 69524463 T 19950222; JP 2858094 A 19940225; KR 19950003639 A 19950224; US 39432395 A 19950223; US 83997597 A 19970424